Dispose currentLocalColorTable in final block

Author: brianpopow

src/ImageSharp/Formats/Gif/GifDecoderCore.cs

@@ -463,6 +463,7 @@ private void ReadFrame<TPixel>(BufferedReadStream stream, ref Image<TPixel>? ima
         finally
         {
             indices?.Dispose();
+            this.currentLocalColorTable?.Dispose();
         }
     }